A pot experiment was conducted to study the effects of decomposing leaf litter of Juglans regia on the growth, antioxidase system, and osmoregulation substances content of Triticum aestivum. Each pot contained 8 kg soil mixed with leaf litter (0 g/pot, CK; 30 g/pot, A₁; 60 g/pot, A₂; and 90 g/pot, A₃). Supplementary experiment was conducted as following: Leaf litter of Juglans regia was steamed for 12 h, then soaked in 80% acetone and alcohol for 24 h respectively, and then steamed again for 12 h, the other methods were the same as above. The results showed that: During 0-160 d, the ground diameter, stem height, plant height, and dry weight aboveground of T. aestivum were inhibited significantly, and the inhibition effect was getting stronger with the increasing amount of the leaf litter addition; During 75-115 d, the activity of superoxide dismutase (SOD) increased with the increasing amount of leaf litter, while the activities of catalase(CAT) and peroxidase(POD) under leaf litter treatment were significantly lower than control and the differences between all litter treatments were not significant; During 75-95 d, there was no obvious difference of in leaf Malondialdehyde(MDA) content. On 115 d, the soluble sugar contents of wheat leaf increased significantly with the increasing amount of leaf litter, while the protein contents showed a significant downward trend; The allelopathic compound effects(CE) of all litter treatments were negative, and the inhibition effect was getting stronger over time, bue after 115 d it decreased, the reason might be that the allelochemicals of leaf litter of Juglans regia had obviously reduced or almost no longer released; In supplementary experiment, there was no obvious difference of morphological feature and no significant difference in growth indicators between B₁ (30 g/pot), B₂ (60 g/pot) and CK, and the absolute value of RI under B₃ (90 g/pot) was significantly decreased compared with the one under A₃, this indicated that Triticum aestivum was not significantly inhibited by the effects of leaf litter on soil physical properties and physical barrier of root growth. Taking into account all parameters, the growth and physiological characteristics of Triticum aestivum were significantly affected by the allelochemicals released from the decomposing leaf litter of Juglans regia.